Shutterstock
The space shuttle Discovery on display at its permanent home at the Smithsonian Air and Space Museum, where admission is free all year long.
All visitors need is a Museum Day Live! ticket (available as a free download through The Smithsonian's website), which grants two people access the museum in lieu of general admission costs.
For more information on National Museum Day, head over to The Smithsonian's website, and check out some of the participating museums below:
Adler Planetarium, Chicago, IL
Children's Museum of Manhattan, New York, NY
Edgar Allan Poe Museum, Richmond, VA
Emily Dickinson Museum, Amherst, MA
Harvard Museum of Natural History, Cambridge, MA
Museum of American Finance, New York, NY
New Orleans Museum of Art, New Orleans, LA
San Diego Air and Space Museum, San Diego, CA
Smithsonian National Museum of Natural History, Washington, D.C. (all Smithsonian and Smithsonian-affiliated museums are free)
The Phillips Collection, Washington, D.C.
For a complete list of museums and to find one in your area, click here.